- 2 tbsp. unsalted butter
- 4 pounds medium yukon gold or russet potatoes (10-12)
- 1 cup shredded sharp cheddar cheese (or Gruyere)
- 1 cup grated store-bought parmesan cheese
- 5 cloves of garlic
- 1 medium bunch fresh thyme
- 2 1/4 cups heavy cream
- 1 tsp. salt
- 1 tsp. freshly ground black pepper
- 1/4 tsp. ground nutmeg
Preheat the oven to 350F. Rub 2 tbsp. unsalted butter on the bottom and sides of a 10-inch cast-iron skillet.
Wash the potatoes. Using a mandoline or sharp knife to thinly slice the potatoes. Set aside.
To a large bowl add the cheeses. Mince the garlic and add to the cheeses. Pick the leaves from the fresh thyme and finely chop until you have approx. 4 tsps. and add to the cheese mixture. Add the heavy cream, salt, pepper and nutmeg. Stir to combine.
Transfer about a third of the mixture to the skillet and spread to coat. Arrange a few of the potato slices in a flat spiral to cover the bottom of the skillet. Then stack bunches of the sliced potatoes vertically in the skillet so that you can see most of the edges of the slices. Continue stacking and arranging to use up all the slices.
Spoon the remaining cream mixture evenly over the potatoes. The cream should come about 1/2″ to the top of the skillet. If you have too much, don’t use it all. If you have too little simply add some cream to the skillet.
Place the skillet on a baking sheet. Bake until the top is deep golden brown and the potatoes are tender, 1 hour 40 minutes to 1 hour 50 minutes. You can remove a slice of potato from the center and check for doneness if you are uncertain. Check after 1 hour 15 minutes. If the top is already browned loosely cover the top with aluminum foil and continue baking. Let cool for 10 minutes before serving. Garnish with more fresh thyme if desired.